Theoretical investigations of the hyperfine interactions for Co2+ in the fluoroperovskites

The hyperfine structure constant A of central ion and the superhyperfine parameters A′ and B′ of ligands for Co2+ in LiBaF3, KMgF3, KZnF3 and CsCdF3 are theoretically studied from a cluster approach based on the weak field scheme. The unpaired spin densities for the fluorine 2s, 2pσ and 2pπ orbitals are quantitatively calculated from the molecular orbital and mixing interaction coefficients based on the cluster approach. The experimental A, A′ and B′ as well as the g factor for Co2+ in these fluoroperovskites are satisfactorily explained in a uniform way. The results are discussed.